1. Field of the Invention
The present invention relates to a document processing apparatus, and in particular to the processing of a page carrying printed information such as letter and/or number characters and/or images. The present invention also relates to a facsimile apparatus incorporating such a document processing apparatus.
2. Summary of the Prior Art
In a word processing system, characters or other images may be input into a computer, and displayed on a screen (CRT) to enable the user to edit or otherwise to change the displayed information. That editing is normally carried out using the keyboard, or by a mouse. It is also known to input data to the computer via an optical scanner which can scan a printed document. If a permanent record of the data is needed, the data may be printed on a sheet of paper by transmitting the data from a computer to a suitable printer.
Data may also be input to a computer via a data pad, which has a pen that is movable over the surface of the pad, with the position of the pen being recorded to generate the data. When connected to a computer system, the data may then be displayed on the screen of the system.
In such a word processing system, information is displayed on a screen unless a permanent record is wanted. However, such on-screen display has the disadvantages that the resolution of the display is low, and it is often tiring for the operator to look at such a screen for a prolonged period. Furthermore, such screens usually present only a limited part of a page of a document.
While the document can be, and often is, printed, editing of the printed document by marking the printed sheet then requires the editing to be re-entered into the word processing system via e.g. the keyboard. Thus, effectively, two separate editing operations are carried out. This problem is increased when two or more people wish to edit the document, particularly if editing is to occur at remote sites. While it is possible to print the document at one site, to transmit it to another site for editing, and then return the edited document to the first site for re-entering of the editing into the wordprocessing system, this is troublesome even when use of a facsimile transmission is made.
In wordprocessing systems, the data represents characters to be printed. However, the same problems occur when the data represents images.